Two Russian cosmonauts will venture outside the International Space Station today. During the spacewalk, which begins at 10:40 a.m. ET, flight engineers Fyodor Yurchikhin and Alexander Misurkin will install equipment for the arrival of a new Russian module and begin preparations for the installation later this year of an optical telescope.

The two cosmonauts will exit the Pirs airlock at about 11:40 a.m. for a spacewalk scheduled to last about 6.5 hours. They plan to continue routing power and Ethernet cables for the arrival of the Russian Multipurpose Laboratory Module, which will be launched aboard a Proton rocket from the Baikonur Cosmodrome in Kazakhstan.

They also will install on the Poisk module a panel of experiments designed to collect data on the effects of the microgravity environment in low-Earth orbit. The astronauts will wear Orlon spacesuits, which are not the same spacesuits that U.S. astronauts wear on spacewalks, though the design principles are the same.

Last month on a similar routine spacewalk, Astronaut Luca Parmitano nearly drowned when water seeped into his helmet, impairing his ability to see and hear. NASA is still unsure what caused the leak. It is still conducting intensive forensic work to figure out the cause.